JPH0137997Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a shift device for an outboard motor.

A shift mechanism for switching the direction of power transmission in a conventional outboard motor has a configuration shown in cross section in FIG. That is, a cam groove having a forward cam part F, a neutral cam part N, and a reverse cam part R is formed on the side surface of the shift cam 1 that strokes in the vertical direction by the upper clutch mechanism, and the push rod 2 is inserted into this cam groove.
The end portions of are pressed together under the force of the return spring 3. This push rod 2 is connected to a shift dog 7 which is provided on the outer periphery of a propeller shaft 6 through a push pin 4 and a dog pin 5 so as to be slidable in the axial direction by spline fitting. It is starting to be moved. Then push rod 2 is attached to forward cam part F of shift cam 1.
When the end of the shifter dog 7 is positioned and the shifter dog 7 moves to the left in the figure, it engages with the pawl 9 of the forward gear 8, transmits the rotation of the drive shaft 10 to the propeller shaft 6 as forward rotation, and reverses the reverse cam portion R of the shift cam 1.
When the end of the push rod 2 is located at
When the end of the push rod 2 is positioned on the neutral cam portion N of the shift cam 1 and the shifter dog 7 is placed in the neutral position, the rotation is transmitted to the propeller shaft 6 as reverse rotation. Also, rotation is not transmitted.

Further, there is another conventional shift mechanism shown in FIG. This allows the shifter 1 to move in the axial direction by rotating a shift cam 13, and this movement is transmitted to a shift slide 14 to slide the dog pin 5 and shifter dog 7 via springs 15 and 16.

However, in all of the above, the movement of the shift cam 1 is transmitted to the shifter dot 7 by the force of the spring 3 (see Fig. 1) or 15, 16 (see Fig. 2), so that the movement of the shift cam 1 is transmitted to the shifter dot 7. If the meshing condition is poor, the dog will be pushed back by the large rotational force of the gear, which will cause the teeth to fly and generate an abnormal noise, as well as causing the gear to wear out prematurely. Further, if the spring causes a surging phenomenon or the dock system causes a resonance phenomenon, a problem arises in that the dock moves back and forth between the forward gear 8 and the reverse gear 11.

The present invention was developed with the aim of improving the above-mentioned problems in the prior art.
An object of the present invention is to provide a shift device for an outboard motor that can prevent the generation of abnormal noise and wear of gears.

Hereinafter, an embodiment of the present invention will be described with reference to FIG. 3, using the same reference numerals for parts common to those in FIGS. 1 and 2.

A first spring 15 is interposed at the inner end of the push pin 4 through which the dock pin 5 is inserted, and a second spring 16 is interposed between the push pin 4 and the push rod 2.

As shown in FIG. 4, an orifice 17 consisting of a notch is formed on the circumferential surface of the push pin 4 in the axial direction, and a space before and behind the orifice 17 is filled with oil.

Therefore, by operating the shift cam 1, the push rod 2 moves forward and backward, and the first or second spring 1
The dog gear selectively meshes with the forward gear 8 or the reverse gear 11 through the push pin 4, dog pin 5, and shifter dock 7, which are driven by the push pins 5 and 16, and the forward or reverse drive is transmitted.
When the shifter dot 7 meshes with the gears 8 and 11, the tips of the teeth come into contact with each other, causing the shifter dot 7 to return, and since the springs 15 and 16 both have the force to engage the dog gears, the shifter dot 7 is in the neutral state. Try to return to position and repeat.
When the natural frequencies of the springs 15, 16 match the speeds of the repetitive motions, a resonance phenomenon occurs, causing a surging phenomenon in the springs 15, 16, making the switching operation difficult.

However, in the present invention, as shown in FIG. 4, a notched orifice 17 is provided in the push pin 4 over the entire length in the axial direction. The oil damper functions as a so-called oil damper, regulating the speed at which the shifter dog 7 is pushed back and the amount of movement thereof, thereby helping the shifter dog 7 to mesh normally and smoothly. Orifice 17 is push pin 4
It may be formed with a hole passing through in the axial direction.

In this way, the present invention switches between forward and reverse transmission of driving force to the propeller shaft by moving the push rod using a shift cam to slide the shifter dog on the propeller shaft and selectively engaging the forward gear and reverse gear. By arranging springs before and after a push pin connected to the shifter dog via a dog pin, and by providing an orifice consisting of a hole or notch through which oil flows in the axial direction of the pusher pin, the movement of the shifter dog is prevented from surging. without causing
To provide excellent effects such as smooth gear meshing, eliminating noise caused by grinding when gears are meshing, and preventing wear of gears.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing a conventional shift device, FIG. 3 is a cross-sectional view showing an embodiment of the shift device according to the present invention, and FIG. 4 A and B are cross-sectional views of the push pin in FIG. 3. and a front view. 1...Shift cam, 2...Push rod, 4
... Push pin, 5 ... Dog pin, 6 ... Propeller shaft, 7 ... Shifter dog, 8 ... Forward gear, 10 ... Driving force, 11 ... Reverse gear, 13 ... Shifter, 14 ... Shift slide, 15, 16... Spring, 17... Orifice.

Claims (1)

[Scope of utility model registration request] A push rod is moved by operating a shift cam to slide a shifter dot on the propeller shaft, and selectively engages a forward gear and a reverse gear to switch between forward and reverse transmission of driving force to the propeller shaft. A spring is placed before and after the push pin that is joined via the push pin, and the space in which the spring is accommodated is filled with oil, and an orifice consisting of a hole or notch is provided to allow oil to flow in the axial direction of the push pin. An outboard motor shift device characterized by: